Refinement Database

Database on Refinement of Housing, Husbandry, Care, and Use of Animals in Research

This database, created in 2000, is updated every four months with newly published scientific articles, books, and other publications related to improving or safeguarding the welfare of animals used in research.

Tips for using the database:

  • This landing page displays all of the publications in the database.
  • Use the drop-down menus to filter these publications by Animal Type, Setting, and/or Topic.
  • Clicking on a parent category (e.g., Rodent) will include publications relating to all the items in that category (e.g., Chinchilla, Gerbil, Guinea Pig, etc.).
  • You may also add a keyword to further narrow your search.
  • Please note that at this time, only publications dated 2010 or later (with some exceptions) can be filtered by Animal Type and Topic, and only publications dated 2020 or later (with some exceptions) can be filtered by Setting. Most publications older than 2010 can only be searched by keyword. 
Earl, S. C., Hopper, L. M., Ross, S. R. 2020. Same space, different species: The influence of exhibit design on the expression of zoo-housed apes’ species-typical retiring behaviors. Animals 10(5), 836.

Wild chimpanzees frequently make arboreal nests, while wild lowland gorillas typically nest on the ground. We aimed to understand whether zoo-housed apes’ use of elevated spaces for retiring similarly differed between species and across exhibits...

Hambrecht, S., Oerke, A.‐K., Heistermann, M. et al. 2020. Diurnal variation of salivary cortisol in captive African elephants (Loxodonta africana) under routine management conditions and in relation to a translocation event. Zoo Biology 39(3), 186–196.

The present study assessed the diurnal variation in salivary cortisol in captive African elephants during routine management (baseline) and in relation to a potential stressor (translocation) to evaluate to what extent acute stress may affect...

Reinhardt, V. (ed.) 2020. It’s Okay to Cry - Discussions by the Laboratory Animal Refinement & Enrichment Forum [LAREF], Volume V. Animal Welfare Institute, Washington, DC.

This is the 5th volume of selected discussions that took place on the electronic Laboratory Animal Refinement & Enrichment Forum between February 2016 and December 2019. The forum was created in October 2002; it allows...

Shomer, N. H., Allen-Worthington, K. H., Hickman, D. L. et al. 2020. Review of rodent euthanasia methods. JAALAS 59(3), 242–253.

The optimal choice of euthanasia method for laboratory rodents depends on a number of factors, including the scientific goals of the study, the need to minimize animal pain and/or distress, applicable guidelines and laws, the...

Acharya, R., Rault, J.-L. 2020. Risk factors for feather-damaging behavior in companion parrots: A social media study. Journal of Veterinary Behavior 40, 43-49.

Studies on the etiology of behavioral problems often involve interference in the animal's routine or reliance on owners' self-reports like surveys. Gathering data from videos posted on social media, a technique coined ‘video mining’, offers...

Cloutier Barbour, C., Danforth, M. D., Murphy, H. et al. 2020. Monitoring great ape heart health through innovative electrocardiogram technology: Training methodologies and welfare implications. Zoo Biology 39(6), 443-447.

Assessing and treating cardiovascular disease (or heart disease) is a growing concern for institutions housing great apes, as it is a major cause of mortality in all four taxa managed in human care. As part...

Evison, E., McKenzie, A., Holmes, L. 2020. Social and environmental impacts on sleep in captive Asian elephants (Elephas maximus). Zoo Biology 39(6), 397-404.

Modern zoos strive to improve standards of animal management, husbandry and welfare of their animals as part of a continual evaluation process. Elephants (Elephantidae) have received particular attention in recent years due to the challenge...

Axiak Flammer, S., Eskes, C., Kohler, I. et al. 2019. Alternatives to carbon dioxide—Taking responsibility for humanely ending the life of animals. Animals 9(8), 482.

Carbon dioxide (CO2) is commonly used to kill rodents. However, a large body of research has now established that CO2 is aversive to them. A multidisciplinary symposium organized by the Swiss Federal Food Safety and...

Kumar, V., Pradheeps, M., Kokkiligadda, A. et al. 2019. Non-invasive assessment of physiological stress in captive Asian elephants. Animals 9(8), 553.

Asian elephant (Elephas maximus) populations, both in the wild and in captivity, have been continually declining over the decades. The present study examined the physiological stress response of captive Asian elephants in relation to body...

Janiszewski, P., Cilulko-Dolega, J. 2019. Behavior and spatial use of enclosures by does and fawns of farmed fallow deer in postnatal period. Journal of Veterinary Behavior 31, 5-9.

The aim of this study was to determine the hiding preferences of farmed European fallow deer does and fawns in natural sites and artificial shelters during the postnatal period. A total of 270 hours of...

Eichner, M., Garcia, K. 2019. Increase in morbidity and mortality in a shipment of red-eared slider turtles (Trachemys scripta elegans). Laboratory Animals 53(6), 634–640.

A cohort of captive-bred red-eared slider turtles, Trachemys scripta, was received from a commercial vendor. Shortly after arrival, several turtles presented as lethargic with subjectively pale skin and multifocal areas of cotton-like tufts in the...

Edwards, K. L., Miller, M. A., Carlstead, K. et al. 2019. Relationships between housing and management factors and clinical health events in elephants in North American zoos. PLOS ONE 14(6), e0217774.

Elephants experience a number of health issues that can contribute to their well-being and survival. In managed populations, housing conditions and management practices can influence individual health, so potential risk factors associated with morbidity or...

Brown, J. L., Carlstead, K., Bray, J. D. et al. 2019. Individual and environmental risk factors associated with fecal glucocorticoid metabolite concentrations in zoo-housed Asian and African elephants. PLOS ONE 14(9), e0217326.

A recent large-scale welfare study in North America involving 106 Asian (Elephas maximus) and 131 African (Loxodonta africana) elephants at 64 accredited facilities identified links (i.e., risk factors) between zoo environmental factors and a number...

DeNicola, A. J., Miller, D. S., DeNicola, V. L. et al. 2019. Assessment of humaneness using gunshot targeting the brain and cervical spine for cervid depopulation under field conditions. PLOS ONE 14(2), e0213200.

Population reduction or eradication of domestic or non-domestic species may be required to address their impacts on the environment, other species, or human interests. Firearms are often used to accomplish these practical management objectives, and...

Anderson, J. R., Ang, M. Y. L., Lock, L. C. et al. 2019. Nesting, sleeping, and nighttime behaviors in wild and captive great apes. Primates 60(4), 321–332.

The past few decades have seen a burgeoning of scientific studies on great apes’ use of nests for sleeping in the wild, as well as their nesting behavior and sleep in captivity. We review recent...

Scott, N. L., LaDue, C. A. 2019. The behavioral effects of exhibit size versus complexity in African elephants: A potential solution for smaller spaces. Zoo Biology 38(5), 448-457.

Population-level analyses suggest that habitat complexity, but not necessarily space availability, has important welfare outcomes for elephants in human care. At the Dallas Zoo, the opening of a new exhibit complex allowed us to measure...

Cox, R. J., Nol, P., Ellis, C. K. et al. 2019. Research with agricultural animals and wildlife. ILAR Journal 60(1), 66-73.

In fiscal year 2016, agricultural animals such as swine, sheep, goats, and cattle represented 10% of the 820 812 animals used in USDA-regulated research. In addition to traditional agricultural animals, research studies using captive wildlife...

Fischer, C. P., Romero, L. M. 2019. Chronic captivity stress in wild animals is highly species-specific. Conservation Physiology 7(1), coz093.

Wild animals are brought into captivity for many reasons—conservation, research, agriculture and the exotic pet trade. While the physical needs of animals are met in captivity, the conditions of confinement and exposure to humans can...

Schiffmann, C., Hoby, S., Wenker, C. et al. 2018. When elephants fall asleep: A literature review on elephant rest with case studies on elephant falling bouts, andpractical solutions for zoo elephants. Zoo Biology 37(3), 133–145.

Little attention has been paid to the resting and sleeping behavior of zoo elephants so far. An important concern is when elephants avoid lying down, due to degenerative joint and foot disease, social structure, or...

Phillips, C. J. C., Farrugia, C., Lin, C.-h. et al. 2018. The effect providing space in excess of standards on the behaviour of budgerigars in aviaries. Applied Animal Behaviour Science 199, 89-93.

Budgerigars housed in conventional cages have no opportunity for some normal behaviours, in particular flight, and develop stereotyped behaviours. Increasingly aviaries are used for groups of budgerigars but the minimum space requirement to support normal...

Fuller, G., Allard, S. 2018. Preliminary data showing potential for salivary C-reactive protein as an indicator of welfare in western lowland gorillas (Gorilla gorilla gorilla). Journal of Veterinary Behavior 28, 58-62.

C-reactive protein (CRP) is an acute phase protein often used as a biomarker for inflammation related to acute trauma or chronic illness. Animal studies showing elevations in CRP following events such as road transport and...

Unakafov, A. M., Möller, S., Kagan, I. et al. 2018. Using imaging photoplethysmography for heart rate estimation in non-human primates. PLOS ONE 13(8), e0202581.

For humans and for non-human primates heart rate is a reliable indicator of an individual’s current physiological state, with applications ranging from health checks to experimental studies of cognitive and emotional state. In humans, changes...

Wall, E. L., Hartley, M. 2017. Assessing enclosure design and husbandry practices for successful keeping and breeding of the Burmese brow antlered deer (Eld’s deer, Rucervus eldii thamin) in European zoos. Zoo Biology 36(3), 201–212.

The endangered Burmese brow antlered deer (Rucervus eldii thamin) is a medium sized tropical cervid kept in a number of European zoos. Studbook data and anecdotal reports have suggested that this species suffers from poor...

Monreal-Pawlowsky, T., Marco-Cabedo, V., Manteca, X. et al. 2017. Environmental enrichment facilitates release and survival of an injured loggerhead sea turtle (Caretta caretta) after ten years in captivity. Journal of Zoo and Aquarium Research 5(4), 182-186.

In June 2006 a loggerhead sea turtle (Caretta caretta) was admitted to a rescue centre on the Mediterranean coast with severe fishing net entanglement in its fore right flipper. The flipper could not be saved...

Holdgate, M. R., Meehan, C. L., Hogan, J. N. et al. 2016. Walking behavior of zoo elephants: Associations between GPS-measured daily walking distances and environmental factors, social factors, and welfare indicators. PLOS ONE 11(7), e0150331.

Research with humans and other animals suggests that walking benefits physical health. Perhaps because these links have been demonstrated in other species, it has been suggested that walking is important to elephant welfare, and that...